Hi Noah!
Okay, so the other set of joycons are having the same issue? I still think it's Joy-Con related, because the same issue came up later on and not immediately.
Unfortunately, the right Joy-Con does have the actual button soldered on the motherboard...
Now, there are 2 things to do, to get it working again. If the button didn't fall of the motherboard (this is a common issue for the Right Joy-Con). If this happened, then it's for the best to replace the motherboard.
Option 1: De-Solder the R button from the motherboard and solder a new one in (this can only be done if the traces are still OK).
Option 2: Replacing the motherboard (this is more expensive, but easier).
R button part: https://www.aliexpress.us/item/325680520...
Motherboard part: https://www.aliexpress.us/item/325680689... (A2 is right).
Good luck with the repair and please let us know how it goes!